Mud pressure gauge protective device for oil drilling rig



Dec. 10, 1968 v. P. BRouGHToN 3,415,123

MUD PRESSURE GAUGE PROTECTIVE DEVICE FOR OIL DRILLING RIG Filed Dec. 42. 1966 INVENroR. Vamo/v Q 5mg/rom United States Patent O 3 415,123 v MUD PRESSURE GAGE PROTECTIVE DEVICE FOR OIL DRILLING RIG Vernon P. Broughton, P.O. Box 313,

Sinton, Tex. 78387 Filed Dec. 2, 1966, Ser. No. 598,720 4 Claims. (Cl. 73-395) ABSTRACT OF THE DISCLOSURE A protective attachment in the form of a piston mounted within a body member to be connected -between an oil well drilling pipe and a pressure gauge to prevent drilling mud from entering the pressure gauge while allowing the drilling mud pressure to be transmitted to the gauge.

This invention relates to gauge protective devices, and more particularly to a device for use in conjunction with a pressure gau-ge and adapted to be connected to an oil well drilling pipe to indicate the drilling mud pressure, but at the same time, prevent the drilling mud from entering the pressure gauge.

A main object of the invention is to provide a novel and improved protective attachment adapted to be connected between an oil well drilling pipe and a pressure gauge for preventing the entry of drilling mud into the mechanism of the pressure gauge while at the same time, allowing the mud pressure to be accurately indicated by the gua-ge, the device being relatively simple in construction, being easy to install, and providing accurate indications of drilling mud pressure.

A further object of the invention is to provide an improved protective pressure-transmitting attachment adapted to be connected between an oil well drilling pipe and a pressure gauge for indicating the mud pressure in the drilling pipe, the device being provided with improved means for preventing drilling mud from entering the mechanism f the pressure gauge while, at the same time, allowing the mud pressure to be accurately indicated on the gauge, the device being further provided with means for flushing out portions thereof to prevent malfunctions due to leakage and to maintain the device in good operating condition over long periods of time.

A still further object of the invention is to provide an improved gauge protector for use as a protective attachment between an oil well drilling pipe and a pressure gauge, the protective attachment involving inexpensive components, being durable in construction, and being relatively compact in size.

Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein the single figure is a vertical cross-sectional-view taken through an improved gauge-protective device constructed in accordance with the present invention, shown connected to a pressure gauge for indicating the mud pressure in an oil well drilling pipe.

Referring to the drawings, 11 generally indicates an improved protective device constructed in accordance with the present invention. The protective device 11 comprises a tubular main body 12 which is provided at one end thereof `withexternal threads 13 adapted to be threadedly-engaged in the internally-threaded top head member 14 of an oil well drilling pipe 15, shown in dotted View. The top end of the tubular body 12, as viewed in the drawing, is internally-threaded to receive a flanged plug 16, the plug 16 being provided with the annular sealing gasket ring 17 mounted subjacent the flange or head portion 18 thereof. Thus, as shown in the Figure, when the plug 16 Cil 3,415,123 Patented Dec. 10, 1968 is tightened so that the flange 18 thereof engages the to-p rim of body 12, the sealing rin-g 17 makes sealing contact with the top portion of the bore of body 1 2 immediately above the internal threads thereof.

Plug 16 is formed with an axial bore 19 which is internally-threaded at its upper portion to receive the externally-threaded lower end of a nipple 20. The externallythreaded top end portion of nipple 20' is threadedlyengaged in a T-fitting 21. The top branch of the T-fitting 21 is connected through a conventional conduit connector 22 and a flexible conduit 23 to a conventional pressure gauge 24. The intermediate branch 25 of the T-fittingv 21 is provided with a fluid-inlet fitting 26 provided with a check valve 27, for admitting pressure-transmitting fluid into the portion of the device 11 in direct communication with the pressure gauge 24, as will be presently described.

Designated at 28 is a spool-shaped sliding piston which is provided inside the tubular body 12, the piston having the top and bottom head portions 29 and 30 which are substantially cylindrical in shape and which are peripherally-grooved to receive respective pairs of resilientlydeformable annular sealing rings 31 and 32 making sealing, sliding contact with the inside bore surface of body 12. A coiled spring 33 extends through the bore 19 of plug 16, bearing between the bottom rim of nipple member 20 and the top head elements 29 of the spool-shaped member 28, the bottom ends of the spring enga-ging around a boss 34 provided centrally on the top head member 29.

The spool member 28 is limited in its downward movement by the provision of a stop ring 35 mounted in the lower end portion of body 12, as shown in the gure, upward movement of the spool-shaped member 28 -being limited by the engagement of the top head member 29 with the bottom of plug 16. The annular clearance space defined between upper and lower head portions 29 and 30, shown at 36, has a length somewhat greater than the length of permissible axial movement of the spool-shaped member 28, namely, somewhat greater than the distance between the top end of the spool member and the bottom of the plug 16. Connected to the intermediate portion of `body member 12 at a location so as to be in constant communication with the space 36 is a flush water-inlet conduit 37, `and connected to Ibody 12 diametrically opposite the inlet conduit 37 is a flush water-outlet conduit 38. As above-mentioned, the axial length of the space 36 is sufficiently great so that it will be in communication with the conduits 37 and 38 at all times, regardless of the displacement of the member 28 in the body 12.

In operation, a quantity of pressure-transmitting fluid, such as oil, or the like, is admitted into fitting 21 through the connection 26 to fill the space above the spool-shaped piston 28 leading to the pressure gauge 24, so that any upward movement of the spool-shaped member 28 will be positively transmitted by said pressure-transmitting fluid, namely, the hydraulic liquid employed, to said gauge 24. The `spring 33 biases the spool-shaped piston 28 downwardly substantially to the depressed position thereof shown in the figure. The degree of mud pressure in the oil well drilling pipe 15 will be registered on the gauge 24, since the mud pressure will cause the piston 28 to rise in accordance with the amount of said mud pressure, and the upward movement of the piston will be transmitted throu-gh the hydraulic liquid above the piston to gauge 24. Said hydraulic liquid, shown at 41, is substantially incompressible, and, therefore, the upward movement of piston 28 will be positively transmitted to gauge 24 lby the compression developed in the liquid 41. During operation, flushing water may be passed through the device :by admitting same through conduit 37 into the space 36 and allowing the flushing water to discharge through the conduit 38, carrying therewith any foreign particles, such as mud particles, or the like, which may have leaked into space 36 past the bottom sealing rings 32. This prevents such foreign material from passing through to the pressure gauge 24, thereby protecting such pressure gauge from damage or from improper or faulty operation. With the arrangement illustrated in the drawing, iiushing water may thus be continuously pumped through the device to carry off any mud or other foreign material leaking into space 36. However, if so desired, the water-flushing feature may be omitted and the inlet connection conduit 37 plugged Or sealed oli" and a leak-detecting pressure gauge S connected to the outlet conduit 38, as shown in dotted view. This would provide an indication of fluid leakage past the sealing rings of the spool-shaped piston 28.

While a specific embodiment of an improved protective device for a mud pressure gauge for an oil drilling apparatus has been disclosed in the foregoing description, it will be understood that various modifications within the spirit of the invention may occur to those skilled in the art. Therefore, it is intended that no limitations be placed on the invention except as defined by the scope of the appended claims.

What is claimed is:

1. A protective device adapted to be connected between Aan oil well drilling pipe and a mud pressure-indicating gauge comprising a tubular main body, means to connect one end of said main body to an oil well drilling pipe, conduit means connected to the other end of said main body for connecting said main body to a pressureindicating gauge, a pressure-transmitting piston slidably and sealingly-mounted in said main body, means to admit pressure-transmitting liquid into said conduit means and the space in said main body leading from said piston to said conduit means, spring means biasing said piston t0- ward said one end of the main body, stop means limiting said piston to a normal position adjacent said one end of the main body, said piston being reduced at its intermediate portion to dene an annular space of substantial axial length, a flushing liquid-inlet conduit connected to the intermediate portion of said main body in communication with said annular space, and a flushing liquid-outlet conduit connected to said main body opposite said inlet conduit.

2. The protective device of claim 1, and wherein the axial length of said piston reduced intermediate portion is greater than the permissible axial movement of the piston in said main body.

3. The protective device of claim 2, and wherein said means to admit pressure-transmitting liquid comprises a conduit fitting, means communicatively-connecting said conduit iitting to said conduit means, and an intake check valve in said conduit fitting.

4. The protective device of claim 3, and wherein said main body is provided with an annular top screw plug, said conduit means being threadedly-engaged centrally in said screw plug, and wherein said spring means comprises a coiled spring having one end engaged centrally in said screw plug and bearing on said conduit means, the other end of said coiled spring bearing on said piston.

References Cited UNITED STATES PATENTS 7/1958 Leefer 73-419 XR 9/1963 Trostel 73-395 XR 

